Method for fixing a functional element, particular a seal, to a glass pane of vehicle glazing

ABSTRACT

In order to attach a functional element, particularly a seal, to a glass pane, particularly a glass pane of vehicle glazing, an adhesive is applied to a predetermined surface region of a clip. Every clip is set into a predetermined position on the surface of the pane provided for this purpose. After the adhesive has cured, the functional element is engaged with the clips with a positive lock, and afterwards, a connection region that is common to the clips, the functional element, and the glass pane has a sealing compound cast onto it, using the free casting method, and is at least partially covered when this is done.

The invention relates to a method for attaching a functional element,particularly a seal, to a glass pane, particularly a glass pane ofvehicle glazing.

In the case of vehicle glazing, the edges of glass panes are surroundedwith functional elements, particularly seals, and the glass panesequipped with seals in this manner can then be inserted into thecorresponding car body openings of the vehicles by the vehiclemanufacturer.

It is known to injection-mold functional elements such as seals, holderframes, covers, or the like onto glass panes, i.e. to connect suchelements with the panes by directly extruding them on. However, thismethod has the disadvantage that the absolute shape retention of thefunctional elements, e.g. of the seal profile with the correspondingsealing lips, cannot be guaranteed during its shaping by means ofextrusion onto the pane. For this reason, the use of pre-finished sealsor seal profiles is generally preferred. In order to be able to reliablyand permanently connect such pre-finished functional elements with aglass pane, first of all it is necessary to bring the pane and thepre-finished functional element together. In this connection, thefunctional element must also be positioned on the glass pane in theorientation, location, and position intended for this purpose. Thefunctional element must then be held in the predetermined position untilit is permanently attached to the glass pane, for example due to bindingor curing of connecting adhesive that was applied. Afterwards, the glasspane, prepared in this manner, can be passed on to further use. It isusual to use appropriate devices, gages, and similar assembly aids, forbringing together the parts to be connected with one another, the glasspane, on the one hand, and the seal as a functional element, on theother hand, positioning them, and holding them. Making appropriatelyconfigured, operationally reliable devices and/or assembly aidsavailable requires not insignificant investments as well as subsequentlyincurred maintenance and repair costs.

The invention is based on the task of finding a method for attaching afunctional element, particularly a seal, to a glass pane, preferably forvehicles, in which it is possible to do without the use ofcost-intensive devices and/or assembly aids and similar aids forcontrolled holding and/or positioning of the parts to be connected withone another.

This task is accomplished, according to the invention, by means of amethod having the characteristics of claim 1.

Advantageous further developments and embodiments of the sequence ofmeasures to be carried out as indicated in claim 1 result from thedependent claims 2 to 11.

It is an essential principle of the invention to use a clip to beattached at a predetermined location of the glass pane as anintermediate holder, before positioning the functional element on theglass pane. The functional element can be attached, i.e. engaged to theclip by means of a suitable positive-lock connection, whereby thefunctional element sits in its predetermined position on the glass paneas soon as it has locked into the clip that is already seated on theglass pane. Subsequently, final securing of the connection between glasspane and functional element still takes place, in that regions on theouter surfaces of clip, functional element, and glass pane selected forthis purpose have the sealing compound poured around them, in a freecasting process, whereby the connection region common to clip,functional element, and glass pane is at least partly covered by thesealing compound.

Several clips can be disposed next to one another, in a row, on theglass pane. It is possible to assign a related clip to each functionalelement. Every clip can be produced as an injection-molded part made ofplastic, for example of polypropylene, having a Shore hardness of 40,for example.

Every clip can consist of a foot that is plate-shaped, for example, fromwhich a mushroom-shaped engagement element rises up. The surface of theplate-shaped foot of the clip that faces away from the engagementelement can be coated with adhesive. Of course, any other embodiment ofa clip is possible, as long as it is suitable for being used to carryout the method.

For this purpose, the functional element has a positive-lock element,for example a depression, a groove, or the like, which can engage withthe clip, at a location provided therefor. With this depression orgroove, it is possible to press the functional element onto the clip,i.e. onto its engagement element, so that functional element and clipare engaged with one another with a positive lock.

If the clip has previously been attached to the glass pane withadhesive, a type of preliminary connection between functional elementand clip has been created by the clip, bringing about a predeterminedpositioning, i.e. fixation of the functional element on the glass pane,in each instance.

The final connection, i.e. securing of the connection of the functionalelement with the glass pane then takes place by means of the sealingcompound that is applied to glass pane, parts of the clip, and parts ofthe functional element, using the free casting process.

Preferably, a curable polyurethane is used as the sealing compound.Single-component as well as two-component mixtures are suitable for thesealing compound.

By means of applying the sealing compound using the free castingprocess, projections, undercuts, surfaces and similar positive-lockelements that are located on the clips, the functional element, and theglass pane, specifically in the same connection region, are clamped toone another by means of curing of the sealing mass.

It is particularly advantageous if an extruded profile configured as aclip bar is used for the clips when implementing the method according tothe invention. The clip bar is therefore a pre-finished endless part,produced using the extrusion process, for example, which is either cutto a desired length, in each instance, before being connected with theglass pane, or can also be shortened accordingly by means of a cuttingstep, in each instance, while being connected with the glass pane.

The clip bar, just like every individual clip, can, of course, also havea depression as a positive-lock element that serves for engagement withthe functional element. For example, a clip bar having an approximatelyV-shaped or U-shaped cross-section is possible, in which one U shankforms the surface that can be coated with adhesive, and the other Ushank acts more or less with elastic resilience. Such a U-shaped clipbar can be attached to the glass pane by means of gluing, for example,in such a manner that an engagement element that projects from acorresponding functional element can be pushed in from the side, whilethe U shank of the “U” that is essentially lying down is spread openwith elastic resilience. At least one of the two U shanks can have athickened part in the region of its free end, which projects relative tothe other U shank, in each instance, by means of which the gap betweenthe U shanks is reduced. In this way, the engagement effect is producedor improved.

Every clip or every clip bar can be glued to the surface of a glasspane, in each instance, using a suitable adhesive.

It is particularly advantageous to use a hot-melt glue as an adhesivewhen implementing the method according to the invention. Hot-melt glueshave the advantage that they harden rapidly and offer the possibility ofconnecting the clip with the glass of the pane, for example without theprior application of a primer.

Hot-melt glues furthermore have the advantage that they can bereactivated at any time, even after they have already been applied, forexample by applying heat. But other adhesives could also be redissolvedafter they have already dried, for example by applying a solvent, andthereby reactivated.

This possibility of reactivation of the adhesive is particularlyadvantageous when using clip bars, since these can be kept on hand ordelivered as a pre-finished product, i.e. already provided withadhesive, for example in rod form or in roll form.

At the site of use, all that is then required is reactivationimmediately before being set onto the glass pane.

Every clip or every clip bar can, as soon as it has been coated withadhesive, be brought to the glass pane and set onto it in apredetermined position, by means of a computer-controlled device. Thecomputer-controlled device can be, for example, a usual industrial robotthat has been appropriately programmed. Such an industrial robot canpick up every clip or every clip bar, individually, at the locationwhere it is made available, bring it to an application station foradhesive, and subsequently bring it to glass panes that are located on aconveyor belt, for example, as well as set the clip or the clip bar onthe glass pane in the predetermined position.

The functional element can also be brought in, positioned, and engagedwith a positive lock with the clips or the clip bar that is/are locatedon the glass pane, by means of a similar computer-controlled device. Ofcourse, however, it is also possible to set the functional element onand engage it manually.

It is also advantageous to use a computer-controlled device for applyingthe casting material to the connection region. For example, anindustrial robot can pick up the glass pane that has been fitted withfunctional elements according to the invention, and bring it past amouthpiece for sealing compound that is exiting from it, whereby theglass pane performs predetermined, computer-controlled movementsrelative to the mouthpiece. Likewise it is, of course, also possible,vice versa, to move the mouthpiece along the connection region to whichthe casting material is to be applied, under computer control.

A combination of controlled pane movement and mouthpiece guidance isalso possible for application of the sealing compound.

After the sealing compound has cured, the functional element is securelyconnected with the glass pane, and by surrounding the clips or the clipbar, unintentional release of the clip connection, for example due toelastic resilience, is prevented to a great extent. After the sealingcompound has cured, the clip is only minimally involved in the holdingfunction between the functional element and the glass pane any longer.The cured sealing compound has taken over the significant portion of theholding function.

Exemplary embodiments of the invention, which show additional inventivecharacteristics, are shown in the drawing. This shows:

FIG. 1 a cross-sectional view of a roof frame of a vehicle body with aninserted glass pane, at the edge of which a functional elementconfigured as a seal is attached in the manner according to theinvention, and

FIG. 2 a cross-sectional view of the attachment region of a windshieldthat has been set into a vehicle body, whereby a functional element ispositioned and attached on the windshield by means of the methodaccording to the invention, and whereby the clip or clip bar used has anapproximately U-shaped cross-sectional shape.

FIG. 1 shows part of a roof frame 1 of a vehicle body, not shown ingreater detail, in a cross-sectional view. A glass pane that is insertedinto the roof frame 1 is referred to as 2. The gap between edge 3 of theglass pane 2 and the roof frame 1 is sealed with a functional element 4that is configured as a seal 5.

The seal 5 consists of relatively soft, cellular plastic. The seal 5 isan endless profile that has been produced using the extrusion method.Using the so-called co-extrusion process, a predetermined region of thefunctional element 4, here the seal 5, is molded onto the functionalelement 4, the seal 5, as a so-called attachment segment 6. Theattachment segment 6 consists of a hard plastic. An undercut groove ismolded into the attachment segment 6, in its side that faces the glasspane 2.

The reference symbol 7 refers to a clip that consists of a foot plate 8,from which a projection 9 that is mushroom-shaped in cross-sectionrises. The foot plate 8 of the clip 7 is attached to the glass pane 2 ina predetermined position with adhesive 10, preferably a hot-melt glue.After the clip 7 has been attached, the functional element 4 can beconnected with the clip 7 and thereby with the glass pane 2, in that theattachment segment 6 is pressed onto the projection 9 of the clip 7,whereby the projection 9 of the clip 7 engages with the attachmentsegment 6 with a positive lock.

As soon as the functional element 4 has been positioned on and attachedto the glass pane 2 in the manner described above, the connection regionthat is common to the functional element 4, the clip 7, and the glasspane 2 is covered with a sealing compound 11 of polyurethane, using thefree casting method. For this purpose, the glass pane 2 with thefunctional element 4 seated on it is held approximately vertically, insuch a manner that the edge 3 with the functional element 4 located onit is in a relatively low position, at the bottom. In this connection,the projecting nose 12 of the functional element 4, which is molded on,the attachment segment 6, as well as the foot plate 8 of the clip 7,and, finally, the glass pane 2, form a groove into which the sealingcompound 11 can be freely cast. After it has cured, the freely castsealing compound 11 forms a wedge of sealing compound 11 that partiallycovers the glass pane 2, the clip 7, and the functional element 4, whichwedge produces or secures the connection between glass pane 2 andfunctional element 4.

FIG. 2 shows a view of the attachment region of a windshield set into avehicle body, in cross-section. Here again, only sheet metal parts 13and 14 of the vehicle body can be seen. The windshield consists of theglass pane, again referred to as 2.

In this embodiment, the functional element 4, which again is present asa seal 5, has projections 9′ molded on by means of coextrusion, forengagement with a clip 7, as well as an accommodation 15 for engagementwith a projection 9″ of a water tank cover 16 that sits next to the edge3 of the glass pane 2.

The functional element 4, the seal 5, furthermore has additional sealingsegments 17 and 18 in this exemplary embodiment. The functional element4 therefore comprises the seal 5 with the sealing segments 17 and 18 ofsoft, preferably cellular plastic, as well as the projection 9′ and theattachment segment 6 of hard plastic.

The parts of hard and soft plastic can easily be shaped as an extrudedprofile, using the coextrusion method, in the production of thefunctional element 4.

In this exemplary embodiment, a clip 7 is connected with the glass pane2, which clip has an approximately U-shaped cross-sectional shape. Theclip 7 according to FIG. 2 has a U shank 19 that corresponds to the footplate 8 of the clip 7 according to FIG. 1, as well as a second U shank20, which has a head-like thickened part 21 at its free end.

In order to connect the U-shaped clip 7 with the glass pane 2, the Ushank 19 is coated with adhesive 10, preferably a hot-melt glue, and setonto the glass pane 2. Once the clip is seated in its predeterminedposition on the glass pane 2, the functional element 4, which again mustbe connected with the clip 7, will also assume its predeterminedposition on the glass pane 2.

In order to connect the functional element 4 with the clip 7 that isseated on the glass pane 2, the functional element 4 is pushed from theside, from the left, between the U shanks 19 and 20, whereby the U shank20 can be spread open with elastic resilience, until the nose 12 hasengaged with the engagement projection 22 of the projection 9′.

As soon as the functional element 4 is seated on the glass pane 2 in itspredetermined position, using the clip 7, free casting with the sealingcompound 11 again takes place.

Free casting is easily possible if the glass pane is held in such amanner, while this is being done, that the clip 7, which holds thefunctional element 4 and is attached with adhesive 10, is located on itstop. The glass pane 2 would assume this position if the drawing withFIG. 2 is rotated by 180°.

Once the sealing compound 11 has cured, it has surrounded the clip 7 aswell as the projections 9, 9′, 9″ of the functional element 4. Inparticular, the U shank 20 can hardly spring open at all, so that it isonly barely possible for the engagement of the projection 9′ to comeloose from the clip 7.

The sealing compound 11 furthermore also connects functional element 4and clip 7 with the glass pane 2, so that a relatively secure and rigidconnection has been formed, which is furthermore also advantageous for asecure hold of the water tank cover 16 in the case of a windshield.

1. Method for attaching a functional element, particularly a seal, to aglass pane, particularly a glass pane of vehicle glazing, wherein anadhesive (10) is applied to a predetermined surface area of a clip (7),that every clip (7) is set onto the surface of the pane (2) intended forthat purpose, in a predetermined position, that after the adhesive (10)has cured, the functional element (4) is engaged with the clips (7) witha positive lock, and that afterwards, a connection region that is commonto the clips (7), the functional element (4), and the glass pane (2) hasa sealing compound (11) cast onto it, using the free casting method, andis at least partially covered when this is done.
 2. Method according toclaim 1, wherein every clip (7) is set onto the pane (2) before theadhesive (10) that was applied has cured.
 3. Method according to claim1, wherein the applied adhesive (10) is reactivated before the clip (7)is set onto the pane (2).
 4. Method according to claim 2, wherein acurable polyurethane is used as the sealing compound (11).
 5. Methodaccording to claim 4, wherein projections (9, 9′, 9″), undercuts,surfaces, and similar positive-lock elements that are located on theclips (7), the functional element (4), and the glass pane (2), in thecommon connection region, are clamped together by means of curing of thesealing compound (11).
 6. Method according to claim 5, wherein anextruded profile configured as a clip bar is used for the clips (7). 7.Method according to claim 1, wherein a hot-melt glue is used as theadhesive (10).
 8. Method according to claim 1, wherein every clip (7)coated with adhesive (10) is brought to the glass pane (2) and set intoa predetermined position there, by means of a computer-controlleddevice.
 9. Method according to claim 1, wherein the functional element(4) is brought up, positioned, and engaged with the clips (7) with apositive lock, using a computer-controlled device.
 10. Method accordingto claim 1, wherein a computer-controlled device is used for casting theconnection region.
 11. Method according to claim 10, wherein amouthpiece for sealing compound (11) exiting from it is guided along theconnection region to be cast by means of the computer-controlled device.12. Method according to claim 10, wherein the pane is held with acomputer-controlled device, and moved in such a manner that theconnection region to be cast is guided past a fixed mouthpiece forsealing compound (11).
 13. Method according to claim 10, wherein amouthpiece for sealing compound (11) exiting from it is guided along theconnection region to be cast, and that the pane (2) is simultaneouslyheld with a computer-controlled device, and moved in such a manner thatthe connection region to be cast is guided past the mouthpiece.